Jacob Zuma has defied calls from the African National Congress (ANC) to quit, bidding to stay on for between three and six months.
Despite “exhaustive discussions” between the leader and his party, they have failed to agree a departure timetable.
ANC general secretary Ace Magashule announced on Tuesday he expected Mr Zuma to “heed” an “order to leave”.
Talks have resumed and the 75-year-old will respond on Wednesday to a vote by the party’s ruling National Executive Committee to sack him.
But despite further negotiations being planned, Mr Magashule said the decision to remove him is “final”.
If Mr Zuma continues fighting the bid to oust him, it could force a vote of no confidence in parliament.
Officials had hoped for a smoother exit because it is an election year next year.
In local polls in 2016, the ANC recorded its worst electoral result since coming to power in 1994.
Mr Zuma’s hold over the ANC was shaken at the end of 2017, when his chosen successor – his former wide – narrowly lost the contest to replace him.
The man elected instead was Cyril Ramaphosa, ANC deputy president and a former trade unionist who was a key ally of Nelson Mandela.